When you search google on this issue there are quite a few people with the same problem - a USB 3 HDD only being recognized in a USB 2 port. Some test to try and isolate the problem:Does it work in another computer's USB 3 ports with the same cable?Does it work with a different USB 3 cable?Is your powered USB hub a USB 3 or a USB 2 hub?

jonb: When you search google on this issue there are quite a few people with the same problem - a USB 3 HDD only being recognized in a USB 2 port. Some test to try and isolate the problem:Does it work in another computer's USB 3 ports with the same cable?Does it work with a different USB 3 cable?Is your powered USB hub a USB 3 or a USB 2 hub?

I have used this HDD for a few years now on another laptop in 3.0 ports and 2.0 ports with the same cable (the one that came with it). No it doesn't work wih a different cable. My powered hub is 2.0.

I went into the BIOS thing and my HDD shows up there with all it's info, it knows its size and how much space is left so it's reading it.

In theory it would be on the Toshiba download page for that model. But at this point I think you are better off working through jonb's troubleshooting steps if you can to narrow down the issue, prior to calling Toshiba so you can give a good statement of the problem. But if you can't do that, it's probably time to call Toshiba anyway and see what kind of response you get.

If it was me I'd play with Toshiba's Sleep and Charge utility and see if some of those settings unaccountably fix the issue, even though in theory those settings should make absolutely no difference. But this could also complicate the issue and muddy the waters for later troubleshooting.

If its a voltage thing (ie the USB 3 port doesnt put out enough juice), then a Y cable would probably work for you. I presume that of the two top plugs (at the top of the Y), only one would be the actual data connection, the other would only pick up the extra power. So you would have to play with such a cable. But it could still be your answer.

Of course if there is a fault with the laptop, that is another issue.

Do you have some other USB drives you can test - just to check if its your particular HDDs requirements that are stopping this working for you in this case.

Nothing is impossible for the man who doesn't have to do it it himself - A. H. Weiler